The court heard Mr McGrath was killed by his son-in-law Colin Pinder who, together with Vera McGrath, burned and buried his remains in the back garden of his Westmeath home.

McGrath served two years and seven months of a life sentence imposed in 2010 for the murder of her husband in 1986.

She was sent to prison today for "processing" but is expected to be immediately released.

Mr Justice Carney said because of the time already served she had a "get out of jail free card".

Last year she was freed from jail after the Court of Criminal Appeal overturned her conviction, because it found prejudicial evidence had been used against her during the trial.

She was tried alongside Pinder who was convicted of manslaughter and jailed for nine years.

The appeal court directed a re-trial in her case but last week she pleaded guilty to a new charge of being an accessory to the killing after the fact.

The plea was accepted by the State.

Mr McGrath was beaten to death at the family home in Coole in Westmeath in March 1986.

His remains were buried in the back garden but later exhumed and burned before being disposed of again.

McGrath told everyone he had abandoned the family and had disappeared.

She also pretended to have been assaulted and had gone to a solicitor to seek a barring order against him.

His death remained secret until 1993 when her daughter Veronica, who saw her husband and mother dispose of the body, told police in the UK what had happened.

She said her then fiancé and her mother had exhumed the remains and kept a fire going for three days to burn the body.

She said they later ground down the bones to powder and some were washed away while others were placed in a tin in the range.

Mr McGrath's partial remains were then recovered and Vera McGrath immediately admitted her involvement in concealing her husband's death.

However, the Central Criminal Court was told it was not possible to prosecute until years later when there were developments in DNA identification of remains.

Defence counsel Patrick Gageby told the court McGrath had always admitted her involvement in the crime and at no stage had there been any effort to say the remains found at Coole were those of anyone other than Mr McGrath.

He did not agree that the State had to wait for advances in forensic science and DNA retrieval to bring a prosecution.

He said Vera McGrath had no previous convictions and had been told years previously that the garda investigation had concluded and there would be no prosecution.

The court was told the maximum sentence for materially assisting after the killing was two years.

She had already served two years, seven months and 16 days in jail.

In a victim impact statement, Mr McGrath's son Eddie said his father was a loving, protective, kind man who had provided him with a stable home, education and guidance.

He said he was never allowed to mention his father's name at home or have pictures of him on the mantelpiece.

Having the initial period of grief extended to 27 years had been unbearable, he said.

His other sons, in a victim impact statement in 2010, said their father had been a kind, pleasant, hard-working intelligent man.

His loss had a "profound effect on us, learning of barbaric way his life was taken away has left us numb with shock".

They said not having a father figure had left them with no direction in life as children and young men.